1. Field of the Invention
The invention in general relates to a telescoping actuator mechanism, and particularly to an improved sealing arrangement therefore.
2. Background Information
Actuators are a common mechanism utilized to produce axial motion in response to pressure from a working fluid. Many actuators take the form of concentric cylinders isolated to the ambient pressure by means of flexible seals. When the pressure of the fluid introduced into the volume between the cylinders exceeds a certain value, the telescopic arrangement of concentric cylinders will extend and thereafter retract when the pressure is relieved.
In those applications where the actuators are frequently cycled, the flexible seals are exercised thereby increasing their useful life. However, in those applications where the actuators are cycled infrequently, the seals tend to loose performance characteristics which can lead to premature degradation or failure of the sealing function.
In the present invention an improved sealing arrangement is provided whereby the seals of the actuator may be exercised without the requirement for extending or retracting the cylinders.